OH man! If it wasn't bumming you out, would be funny. I'm always making fun of the "expert's" bad advise and now I are one. add an extra 0 to it and if asked, "ayuh, its a 660cc. (adding a 6 would be a bad joke but would crack me up)
Really, no one has ever bothered me about it. Here the law changed in 2008 but had much larger then 50cc engines b4 that. But bottom line is your worried and am sure it is every body's goal to be of help.
Remember the line from Animal hose? "Face it, ya messed up an' trusted us"
Want my phone number so ya can yell at me? I'm not making light of this but would love to call a few of the experts my self, snork.